From the U.S. Pat. No. 1,921,003 there is known a press whereby for shaping the stones in the mould a moulding plate having a smooth upper surface is moved under the mould and which is pressed against the bottom of the mould by means of an eccentric mechanism before the mould is set into vibration.
After the mass put into the mould has been compressed sufficiently, the moulding plate is moved from under the mould and a product plate (i.e., a plate on which the shaped products are discharged from the press and are, e.g., conveyed to a drying or storage room) is moved under the mould. At the same time, a spring-suspended table is move upward for supporting the product plate moved under the mould. Following that, the products shaped in the mould are pressed downward out of the mould by means of the stamp, whilst at the same time the spring-suspended table is also moved downward.
When applying such a method of manufacturing products, it is not possible to ensure a constant height of the products shaped in the mould. In particular, on removing the products from the mould there is a danger that the products will be deformed in an undesirable manner between the stamp and the spring-suspended table.
From the U.S. Pat. No. 3,679,340 there is furthermore known a press provided with a vertically adjustable table by means of which a product plate is pressed against the bottom of the mould for shaping products in the mould arranged in a fixed position. Moulding bars may thereby be moved above the product plate into openings provided in the mould for that purpose for forming holes in the products to be shaped.
Also in this case the products are pressed out of the mould by means of stamps after moulding, whilst the table with the moulding plate is thereby moved downward, but also in this case no means have been provided to ensure that the products shaped in the mould keep a constant height.
Paving stones and the like, however, need to have a constant length and width to make possible the pavement of a road surface or the like in a regular pattern, whilst such paving stones usually must be provided with bevelled edges or so-called chamfers. For the thickness dimension the requirements are less strict, as differences in thickness of the paving stones can be absorbed by the sand bed or the like in which the stones are placed. Therefore it has been quite common so far to manufacture such stones lying in a mould, so that the measures of length and width of the stones are determined by the vertical walls bounding the moulding rooms in the mould, so that a constant measure of length and width can be ensured. In particular, with stones having chamfers the stones are thereby shaped in the mould in such a manner that the eventual upper surface of a stone is shaped in the bottom of the mould lying on the moulding plate. Because of this, in practice the upper surface of the stones shaped in such a manner appears to be the least wear-resistant surface of the brick.